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       #1  

    GPS jamming (or spoofing) woes #2

    On 12/1 I took off from OPLA. At approximately 1500' I encountered GPS jamming (or perhaps spoofing). The GPS failure caused AHRS failure and, most significantly, the HSI compass started spinning at a rapid rate and was unusable and the Auto Pilot was failed. The AHRS did not recover. Granted, we did not fly < 200 kts and wings level for 5 minutes. We were more concerned about returning to the airport. Handheld GPS devices were also jammed in this situation. We also received an immediate TAWS warning, which needed to be silenced.


    I can not stress how confusing and disconcerting this scenario was. Takeoff, GPS failure, TAWS collision alert, Auto Pilot disconnect, spinning HSI compass all concurrently.


    In this shared album there is a video of the HSI spinning and other pictures of the event. I am noticing that only AHRS1 is reported as failed. If I'm not mistaken, pressing the "CPL" button would activate AHRS2. However PFD2 was behaving the same way and the CPL button had no effect. I believe I did try CPL and it had no effect on the spinning HSI compass.


    Note that the aircraft says "both on GPS1". However, the GPS position was incorrect.


    Multiple other aircraft reported GPS issues - including Boeings and Airbuses. A second aircraft returned to the airport due to the GPS jamming, and a Gulfstream on approach went missed.


    We returned to the airport, refueled and waited for the GPS jamming to subside. Fortunately I had an SIC and conditions were VMC. Single pilot IMC may have had a worse outcome.

    If anyone has any thoughts or insight into this situation, I would love to hear it.

    After this incident I would STRONGLY recommend you request this failure scenario in the SIM.
  2. Username Protected
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       #2  
    Thanks to Neil Singer who clarified the following:

    1) The CPL button switches which side is controlling the AP, not directly which AHRS (indirectly of course the right PFD is usually set to AHRS 2, but in this case it wasn't based on the photo). I'm not sure you would have needed to press the CPL button. Rather, you could try to switch PFD 1 to AHRS 2. SENSORS-> AHRS SETTINGS.

    2) You appear to have had an AHRS 2 failure at some point before the photo, given the screen is displaying "BOTH ON ATT STBY". As you noted there was not an AHRS 2 FAIL CAS at the time of the photo, so number 2 may have come back on line and been available.

    3) With the PFD on attitude information from the standby instrument, there is no longer heading information available (AHRS 1 and 2 calculate heading, the standby instrument does not as it doesn't have a dedicated magnetometer). The HSI then reverts to ground track from the FMS (magenta TRK upper left corner of HSI area). Without GPS though you had no ground track, which seems to cause a slow spin, rather than an "X" as might be more easy to interpret.

    4) Ultimately it is very problematic that a failure of GPS is causing dual AHRS failures. This is unacceptable behavior, and as you say is a huge safety risk. The AHRS should be able to function without GPS as long as it has valid air data.

    I am concluding that I may have gotten AHRS, HSI heading, Autopilot, and YD back if I took the following steps.

    1. Utilities | FMS Sensors turn off GPS 1 and GPS 2
    2. Kept the wings level for 5 minutes and speed < 200 kts (according to QRH AHRS failure).
    3. As necessary, selected on each PFD "Sensors | AHRS Settings"

    Per my previous jamming event where GPS never recovered, I'm not convinced GPS would have returned after the jamming has subsided without a ground power reset.

    And, the intersting part of the Garmin manual with respect to this situation. Seems like they need an aditional case - GPS position spoofed.

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  3. Username Protected
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       #3  
    The plot thickens.

    I think I can certainly conclude this was GPS SPOOFING.

    This is corroborated with Flightaware tracking log here. The log states I was flying 97 kts for most of the flight - I assure you I was not flying 97 kts at flaps 0. It seems at 9:03:28 the spoofing took effect. It's not clear to me that the spoofing ended at any time during the flight.

    One thing I have observed. GPS jamming and spoofing when I have encountered it has not been effective ground based receivers. E.g. plane started up, GPS taxi info was fine, all no issues. I have observed this two times. Once out of LTAF and another time out of OPLA.

    It appears that the GPS jamming used only effects receivers in the air and not on the ground.
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    #4  
    Which of the GPS jamming/Spoofing was ground based then that makes sense, you need line of sight to receive the signal. The next question is who is doing it.

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       #5  
    When I asked what was up ATC stated, "There are two military aircraft in the area continuing on and one civilian aircraft returning to lahore."

    So, I'm guessing this was done by the Pakistan military. They indicated a "40NM radius of waypoint xxx" was the effected area - which lead me to believe this was a ground based interruption.



    Quote Originally Posted by (Username Protected) View Post
    Which of the GPS jamming/Spoofing was ground based then that makes sense, you need line of sight to receive the signal. The next question is who is doing it.

    (Username Protected)-
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    #6  
    hi (Username Protected) quite a saga. I hope all is well.

    I have a question for the chat in general on GPS Spoofing.. If the GPS antenna designed for receiving signals form satelites on the top of the airplane as i understand even the WAAS is transmitted up to satelites as a correction. So then my question how does one Spoof / Jam form the ground or below the airplane is it a super strong signal or does one have to above the airplane?
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       #7  
    I would also be intrested if anyone knows a lot about spoofing. This article is interesting. I especially like this comment, "Some of the most enthusiastic spoofers are Pokémon GO fans who use cheap SDRs (Software Defined Radios) to spoof their GPS position and catch elusive pokémon without having to leave their room."

    Note that OPLA is close to the Indian border with Pakistan.
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    #8  
    If you haven't seen this site, it's pretty interesting to keep an eye on to see where GPS jamming/spoofing is going on recently...
    https://gpsjam.org/?lat=30.06065&lon...ate=2022-12-01

    It clearly shows significant interference in the OPLA area on 12/1...
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       #9  
    David - awesome find! Thank you!

    Ha, my next flight is over Iraq, Turkey and into Istanbul. Pretty much GPS jamming central. Guess I'll have more data for Emrbaer.


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    Quote Originally Posted by (Username Protected) View Post
    If you haven't seen this site, it's pretty interesting to keep an eye on to see where GPS jamming/spoofing is going on recently...
    https://gpsjam.org/?lat=30.06065&lon...ate=2022-12-01

    It clearly shows significant interference in the OPLA area on 12/1...
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       #10  
    A pilot report GPS spoofing at high altitude.

    "GPS spoofing over Iraq airspace. Event started in the northern region of Erbil. Crew lost navigational integrity over nearly the entire crossing of the ORBB/Baghdad FIR due to enroute high altitude GPS spoofing (falsified position, not jammed as usual). Aircraft then entered full degrade. GPS was 60NM offset, the IRS were considered unreliable. Crews observed 3 or more aircraft affected. ATC was unaware according to crew. Situation was resolved by receiving radar vectors by ATC to fly along the airway."

    I believe spoofing at FL430/450 for the phenom 300 would result in the loss of AP and YD. If I'm not mistaken, this would require a descent to 27,000'.

    Next person caught in spoofing needs to remember to try turning off GPS 1 and 2 and see if it resolves the AHARS problems. I'm guessing there is a 20% chance that will be me....
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    #11  
    I have seen this or similar problems in our PH100 over Salt Lake, day VFR and high 30’s altitude. Lots of fail indications intermittently for about 50 miles. Just went to heading mode and tried to figure out what was really failed. Center said they had no other reports. Hard IFR and low altitude could have turned Salt Lake into Salt creek with the troubles I saw that day. Haven’t seen the problem yet with our 300. I’m curious as to why IRS was considered unreliable from the other poster above. Obviously not a Phenom.
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       #12  
    I am also curious as to why the IRS was considered unreliable. I thought the whole point of the Khaman filter in the IRS was to filter out events like this. I'm guessing many IRS systems haven't been tested for spoofing and just craps out. Unfortunately, because these are rare events, it seems vendors aren't too interested in addressing the issue.
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       #13  
    All. More updates on this.

    There have been multiple reports of GPS spoofing in the middle east reported on OpsGroup. Aircraft with IRS have fallen victim to GPS spoofing to the point the crew did not there location or the current time. There was a report of one event happening oceanic. Apparently the IRS systems

    Embraer just published FOL PHE505-004/23 related to these issues. My view is the FOL is woefully incomplete. This was my email to contact center regarding the FOL:

    Dear Contact Center,

    Please pass my following feedback on to the author of the most recent FOL.


    I operate out of Dubai and have encountered GPS jamming over Iraq and Turkey. I also encountered GPS spoofing in Lahore Pakistan area.


    There are some critical points I believe are missing from your FOL:


    GPS jamming can get the aircraft into a state where it will not recover GPS position, even after exiting the area of Jamming. This has happened to me on two occasions. I now always have a backup GPS device available on the aircraft. I believe there should be a software fix for this as other devices were able to recover GPS position.


    GPS jamming can be intermittent. This can be extremely distracting on approaches as the GPS position is lost and then regained and all the associated CAS messages cycle on and off. This happened to me on approach at a dual use military/civilian airport in Tukiye.


    GPS spoofing causes a spinning compass indication on the HSI allowing for heading navigation only via the backup compass. I have heard other pilots call this the black ball of death as it is extremely difficult to use and just serves as an aid to navigate into terrain. I must admit, I did use this backup compass to get out of a GPS spoofing event.


    GPS spoofing will cause AP FAIL. Hopefully you aren't flying as a single pilot.


    GPS spoofing will cause AHRS 1 FAIL, YD FAIL, and AP Fail. This means no climb above FL270. Or, at altitude require a descent.


    You should include these failure modes in your FOL. Imagine a situation where an aircraft is at an airport with no radar, mountainous terrain, and IMC conditions. GPS spoofing could result in a disaster as ATC would not be able to provide vectors and navigating from the black ball of death is not practiced in training.


    I have been unable to test this theory but I believe in the case of spoofing and intermittent jamming the appropriate course of action would be to disable GPS1 and GPS2. This would allow return of AHRS 1, YD, AP and the CDI compass.


    Please see this album of pictures and videos that documents a GPS spoofing event I had Dec 1, 2022.



    Also, please see this discussion on phenom pilots.


    -(Username Protected)

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